How many characters can I send in a MMS
Standard MMS Message
1500 characters
Unicode MMS Message
500 characters
If a message is longer the allowed number of characters it will be truncated. If a message contains any characters that aren't in the GSM 03.38 character set, the message type will be treated as unicode. (https://en.wikipedia.org/wiki/GSM_03.38)
* Note: Emojis are classed as Unicode characters.